Apple says the iPhone 4S has a CPU that's "up to two times faster" than the iPhone 4. The GPU is said to be "up to seven times faster." We used four benchmark apps to measure CPU and GPU power on both iPhones plus both iPads. Here's what we observed:

Geekbench 2 measures CPU integer, floating point, and memory speed. They combine these into an overall performance rating. (Higher number is faster.)

GLBenchmark 2.1 includes an interesting Egypt 'walkthrough' in High Quality revealing how well the iPhone or iPad handles on-the-fly rendering of textures, dynamic shadows, etc. Higher number is faster.

The above test is a bit unfair since the resolution of the iPhone and iPad is different. Plus we found out that the "Egypt High" test is limited to 60 FPS. So I've added the graph below using the "Egypt Offscreen" test where all high-level scenes are also rendered off-screen, with the same 1280x720 pixel resolution on all devices. This method provides apples-to-apples performance comparison for the embedded GPUs. We are only able to graph results with iPhones and iPads running iOS 5.0.

If you run the above test on your iPad or iPhone, divide the "total frames" result by 113 seconds to get Frames Per Second (FPS).

OpenGL Extensions Viewer (GLview) measures OpenGL graphics speed. There are four different animations that run to give you frame rates. We ran the "Cubes" animation with Transparency, Multisampling, MipMap, Anisotropic filtering enabled. Higher number is faster.

CPU and GPU
The iPhone 4S with the dual-core CPU and dual-core GPU is definitely faster than the iPhone 4. We plan to delve into the performance more deeply, but Geekbench's overall score was 63% to 68% faster, depending on what version of iOS we were running on the iPhone 4.

The iPhone 4S ran GLBenchmark's "Egypt Offscreen 720p" test 5.9 times faster than an iPhone 4 (both running iOS 5). That doesn't confirm the "up to seven times faster" GPU claim, but it is close enough that we're impressed.

More good news: As you can see from the graphs, if you upgrade last year's iPhone 4 from iOS 4.3 to iOS 5.0, you will see improved performance for Javascript and OpenGL based apps. Ditto for the iPad 2.

CAMERA SPEED
We like the new camera lock screen shortcut and the ability to use the volume button to snap the photo. Very nicely done. At the news conference announcing the iPhone 4S, it was said that it takes one second for the camera to be ready to take a photo and a half second to be ready to take the next photo. After upgrading our iPhone 4 to iOS 5, the same is true of it.